Phosphate supplementation in young men: lack of effect on calcium homeostasis and bone turnover.
OBJECTIVE
To examine the effect of phosphate supplements on calcium homeostasis and bone turnover in young men.


METHODS
Study 1 was a randomised, controlled, cross-over trial of 1000 mg elemental phosphate given for one week, with a standard diet of 800 mg/d each of calcium and phosphorus. Study 2 was an escalating dose study of 0, 1000, 1500 and 2000 mg/d elemental phosphate, each given for one week, with a standard diet of 1000 mg/d each of calcium and phosphate.


METHODS
Northern General Hospital, Sheffield.


METHODS
Study 1, 10 healthy men ages 19-32 y. Study 2, 12 healthy men ages 19-38 y.


METHODS
Sodium acid phosphate tablets each containing 500 mg elemental phosphorus (16.1 mmol/d), given with meals.


RESULTS
Study 1, administration of 32.2 mmol/d phosphorus resulted in a mean increase of 13.2 mmol/d urinary phosphorus, a mean decrease of 1.1 mmol/d urinary calcium, and a mean increase of 7 ng/mL in serum intact PTH. There were no changes in serum phosphate, osteocalcin or urinary N-telopeptide excretion. Study 2, administration of 64.4 mmol/d phosphorus resulted in a mean increase of 27.2 mmol/d urinary phosphorus, a mean decrease of 2.4 mmol/d urinary calcium, with no change in serum phosphate, PTH or urinary deoxypyridinoline.


CONCLUSIONS
Phosphate supplementation of the diet does not affect bone turnover in young men.
Whybro
A
A
Department of Human Metabolism and Clinical Biochemistry, University of Sheffield, UK.
Jagger
H
H
Barker
M
M
Eastell
R
R
D000328:Adult; D000596:Amino Acids / Q000652:urine; D016723:Bone Remodeling; D002118:Calcium / Q000097:blood / Q000378:metabolism* / Q000652:urine; D018592:Cross-Over Studies; D004032:Diet; D006706:Homeostasis; D006801:Humans; D008297:Male; D015675:Osteocalcin / Q000097:blood; D010281:Parathyroid Hormone / Q000097:blood; D010710:Phosphates / Q000097:blood / Q000652:urine; D010758:Phosphorus / Q000008:administration & dosage* / Q000652:urine
D000596:Amino Acids; D010281:Parathyroid Hormone; D010710:Phosphates; D015675:Osteocalcin; D010758:Phosphorus; C036020:deoxypyridinoline; D002118:Calcium